Large solid fossil fuel fired boilers are used to generate electricity. These boilers comprise many stages including an economizer, a reheater superheater, and primary and secondary superheater stages. Within each stage are arranged a plurality of parallel boiler tubes which are arranged in spaced rows defining an array. The tubes within each row are also spaced. Often, the tubes of one row are offset relative to those of an adjacent row.
During fuel burning, byproducts are generated which become attached to the exterior surfaces of the tubes, greatly reducing the efficiency of the boiler. These byproducts include slag and ash. The present invention relates to a device for effectively cleaning these deposits from the exterior surfaces of the boiler tubes, particularly the heretofore inaccessible tubes buried within the offset tube banks.